This isn't my first rodeo i've kep advanced fish for over 5 years. The last thing I did was feed them Omega one premium frozen blood worms. it was a very light feeding. when I woke up I went to check on a new 90 gallon i was setting up and i walked slowly by the other tank to check the usual, temperature air etc. i had the pump off and detached as it was leaking. This was only for ten hours. so the only thing in the water plugged in was an Aqueon 250 Pro. i noticed two fish floating. i immediately removed them and noticed they already had a "dead" smell and were stiff. i removed everything from the tank and it seems everything died wherever they were resting some under or in rocks, one in a shell. I'm typing this, numb right now as i've driven over 50 hours collectively to spend over $1000 on these fish. and I'm in shock right now. I lost a female breeder, and a young male Zebra. among some other very rare cichlids. yes i am a fish whisperer they all got along great.

Yes, I found the cause. It's strange to see all this happen at the same time.
Last time we went to our LFS I had my wife pick out dechlorinator. She grabbed showed me what she grabbed and I nodded to her. What I so casually dismissed was an agent to assist in bacteria and tank conditioning not dechlorinator. I had assumed she read that it was tap water conditioner or dechlorinator and to her the title made her think it was. Regardless, the most expensive mistake I've ever had. Neither of us will have again. 5 years down the drain quite literally. I dont know if I'm going to get back into Zebras at this point.